One of the largest collections of vintage-style tees I know of is at t-shirts.com. Their vintage and 80’s sections include more than 400 vintage designs, which is really a staggering figure. Some designs are faux vintage all the way, with fading and aging crafted into the design. Others appear to use new print, just with retro subject matter.
Sometimes it’s for a band (Allman Bros ‘73 Tour, anyone?) and others for a product or beverage that’s no longer made or has since changed logos. Cartoon characters and classic television seem to be popular subjects as well. Even if vintage isn’t usually your thing, it’s worth checking out their tee collection. You may just come across something you like. You may recognize a few, particularly the Guinness tees as having been featured here before.
Most tees are $20, and the ones on sale are usually $10, which is an absolute steal. Be sure to check them out at t-shirts.com.